Process of purifying hydrocarbon oils



The sulfonated UNITED STATES EBNEST 1B. COBB, OE JERSEY CITY, NEW JERSEY,

PM (on NEW messy),

PATENT OFFICE.

ASSIGNOR TO STANDARD OIL COM- OF BAYONNE, NEW JERSEY, A CORPORATION OF NEW PROCESS OF PURIFYINC- HYDROCABBON OILS.

To all whom it may concern:

Be it known that I, ERNEST B. CoBB,'a citizen of the United States, residing at J ersey City, in the county of Hudson and State Of-fNQW Jersey, have invented a new and useful Improvement in Processes of Purifying Hydrocarbon Oils, of which the following is a specification.

The present invention relates to the punfication or refining of hydro-carbon oils and more particularly to such processes involving the use of stron sulfuric acid, such as acid of 66 degrees Be. or fuming acid. It is especially applicable in those cases in which the treatment of the oil is heavy, such as in the manufacture of water white lubricating oils, medicinal oils, and the like. It will be fully understood from the following specification, in which it is described in connection with a specific illustration of its use.

A suitable hydro-carbon oil, for example, a petroleum distillate fraction having a gravity heavier than 28 Be. and a viscosity about 215 at 100 F. (Saybolt) is subjected to successive treatment with, about 5 per cent. by volume of 66 B., sulfuric acid and with 30-35 per cent. by volume of fuming sulfuric acid (20% anhydrid), the treatment with fuming acid being effected in several dumps, say three or four, with approximately equal proportions of the fuming acid, the oil being cooled between dumps. After the treatment with 66 B. acid and after each dump of the fuming acid treatment, the acid sludge may be permitted to settle from the oil and is separated therefrom, carrying with it considerable proportions of the sulfonated compounds produced from the oil. The acid treated 'oil still contains oil-soluble sulfonated compounds. The oil is then treated in an agitator with about sufficient caustic soda solution of 10 to 16 B., or other alkali solutionv to somewhat more than neutralize the acid, say 10%, allowed to set tle, and the spent caustic solution removed. The neutralized oil, which ma bright in the agitator, if desired, has a volume about 60% of the original oil treated. compounds of the oil are, by the neutralization process, converted into soa s, which are largely soluble in the oil.

he treated-oil containing the oil soluble soaps of the sulfonated compounds is next charged into a still, where it is subjectedto Application filed April 28, 1920. Serial No. 377,264.

be blown Patented Aug. 16', 1921.

steam distillation until approximately.95% has been distilled off and collected, a temperature below the cracking point of the oil, say 600 F. or thereabouts bein maintained. The remaining five per cent. 0 residue con tains substantially all of the sulfo compounds originally present in the oil. The distillate obtained, however, may contain hydrogen sulfid, free sulfur, which will develop sulfur odors or tastes "in the oil. In order to remove these sulfur containing substances from the oil, it may be charged into a still, heated to say 400 F. and treated with steam. It may be steamed for from 2 to 4 hours, after having been heated up, the sulfur and sulfur compounds being thereby eliminated and the viscosity and flash point of the oil brought to the desired figure. The oil may then be steamed until it has a viscosity of 220 to 230 at 100 F. a

After the treated oil has been steamed, it is again treated with fuming sulfuric acid in less quantity than that used in the first or compounds treatment. For example, two dumps of7 The oil soluble sulfonated compounds are. 4

converted by this process into soap, which remain in solution in the oil. These sulfonated compounds are only for the reason that the tend to' produce emulsions when mixed with water, but also for the reason that they, interfere seriously with the filtration of the oil, a matter ofimportance particularly in the case of the production of medicinal oils. After the removal of the spent caustic soda solution, the oil is treated with iso-propyl alcohol, preferably utilizing an aqueous solution containin for example, 70 per cent. by volume 0 iso propyl alcohol havin a specific gravity of .81 and 30 per cent. 0 water. About five per obj ectionable, not

cent. by-volume of the iso-propyl alcohol solution is ahd'is then allowed to iettle. Thealcohol solution which settles to the bottom contains file sulfonated, compounds, which are removed with it. Some of the alcohol remains in the oil. This may be recovered by heating temperature. After treatment of the oil in this manner it may be filtered through fuller s earth or a like filtering medium.

Although the present invention-has been described in connection with specific details of-a particular method of carrying it out, it is not intended that these details shall be regarded as limitations upon the scope of the invention, except in so far as included in the accompanying claims.

I claim: l. The rocess of hydro-car on oils which consists in subjecting-the oil to the action of strong sulfuric acid, removing oil soluble sulfonated compounds from the treated oils, again treating the oil with strong sulfuric acid and washing the treated oil with iso-propyl alcohol.

2. The process of treating and purifying hydro-carbon oils which consists in subj ect-s in the oil to the action of strong sulfuric acid, removing o1l soluble sulfonated comounds from the treated 011s, again treating I the oil-withstrong. sulfuric acid and washing the treated 011 w1th an aqueous solution of iso-propyl alcohol.

3. The process of treating and purifying hydro-carbon oils which consists in subjecting the oil to theaction of strong sulfuric .ate to the action washing w1 treating and purifying I acid, separating and distilling off the greater part of the treated oil, subjecting the distillof fuming sulfuric acid, and the treated oil with an aqueous s0- washing a 'lution, of iso-propyl alcohol. the oil to 300 to 350 degrees F., thereby vaporizing the alcohol and condensing it, or-

owing the oil-with steam at about this separating from the oil a er each treatment the oil soluble sulfonated derivative pro-.

final removal being effected by duced, the

th an aqueous solution of isopropyl alcohol.

5. The process of treating and refining hydro-carbon oils which consists in subjecting the oil to treatment with fuming sulfuric acid, separating the treated oil and removing therefrom the oil soluble sulfonated derivatives resulting from the acid treatment, again treating the oil with fuming sulfuric acid, neutralizing and washin the treated oilwith an aqueous solution 0% isopropyl alcohol and steaming the treated oil to remove traces of iso-propyl alcohol therefrom.

6. The process of treating and refining hydro-carbon oilswhich consists in subjecting said oil to fonated compounds produced by said treatment from the treated oil, treating said 011' iso-' r0 1 alcohol.

p ERNEST B. COBB.

treatment with fuming sulfuric acid, removing the 'Oll soluble sul- 

